Set forth are two parts of the Background of Invention which include Technical Field and Background Art.
1. Technical Field
This invention pertains generally to lock washers of expanded, threaded, driven, headed, tool formed, or locked threaded fastener, class 411, and specifically a locking means made from wire material.
2. Background Art
A lock washier is the most economical locking means known. Usually it is an extra added device used to nut lock, or screw lock. Current in use lock washer specifications are contained in American Standard ASA B27.1-1965, internal-external tooth and helical spring lock washers. However, even though widely used, these lock washers have several disadvantages and limitations, as do known art lock washers. Generally, two lock washer material forms are predominant, wire or bar stock material and sheet stock material.
Nut lock patents relating to wire forms of twisted bar materials relative to this invention are included in the following issued patents:
George H. Moore Nov. 8, 1881 U.S. Pat. No. 249,383: WASHER FOR LOCKING NUTS ON BOLTS, consisting of steel axially twisted rectangular merchant quality bar cut into lengths then formed onto ring shape. It has welded closed or open ends, hardened spiral edges which are rigid or inflexible, not to operate as a spring, with optional bar shapes as triangular or hexagon. Original use shown on railroad rail fish plate bolt with threaded nut. Therein, the severe service requirement at elongated fish plate holes needed for rail thermal expansion resulted in improvement patented by:
Alfred H. Read Dec. 12, 1893 U.S. Pat. No. 510,708: NUT LOCK, improvements on George H. Moore patent, polygonal section (5 sided bar shown in patent drawing) of twisted rod or bar hardened and of open ring ends sprung in opposite directions one beveled to form biting corner one end bent and doubled back forming lug portion projecting outward to keep from entering elongated fish plate hole while turning with nut. Nut lock shown has added lower flange for joint stability, but rail movement and repeated hammering were problems, addressed later by:
John E. Lenholt Jul. 28, 1903 U.S. Pat. No. 734,579: NUT LOCK, also shown for rail joint having twisted angular bar ring with open ends sprung in opposite directions, wherein nut has concentric groove featuring inner groove face that is caused to compress against bolt threads by twisted bar edges wedged vertically within smaller size of groove, and also onto the fish-plate surface against which it rests. (Elongated holes not mentioned).
Townsend Hand Nov. 18, 1917 U.S. Pat. No. 1,245,907: NUT-LOCK, also for rail joint with wedged fish plate, wherein spiral threads or grooved rod (multiple thread rod shown), left hand coarse spiral opposite to hand of bolt threads, with ends offset to each other laterally and ring having split ends in washer plane, separated and pointed, and with washer having additional split intermediate in ring plane and separated. Firm and steady pressure between nut and fish plate is explained by splits in resilient material of nut-lock.
Carl G. Olson Mar. 7, 1933 U.S. Pat. No. 1,900,195: SCREW LOCKING ELEMENT, of single strip of elongated wire stock of polygonal section (square shown) and selectively twisted of multiple concentric rings provided with a plurality of teeth for engaging the work in an annular construction formed with a plurality of adjacently positioned coils with up turned sharp ends. Additionally, terminal section not twisted adapted to receive the free extremity of a conductor is contemplated and binding material is interposed between annular surface of outer and inner annular sections.
These above patents show twisted bar edges spiraled or not. Therein spiral rigid edges are opposed, opposite each other. Thus, rigidly presenting washer like spacing, between joint member surface and nut. All show edge angle 90 degrees or more. Ring ends are shown sprung out of plane, chamfered, sharpened, split, extended, coiled or prepared. They mostly depend upon ends biting effects and combined rigid edge contacting for intended locking.
Nut lock patents of not twisted split spring for nut-lock washers are shown following:
William P. Brachmann Jan. 26, 1892 U.S. Pat. No. 467,627: NUT LOCK, an improved lock washer, partly flat washer lightly spherical split ring with sharp special enlarged inclined biting tooth on one side only ends out of body plane to achieve spring action. Used for fish plate rail joint on bolt between plate and nut face, for nut being "screwed up" to tighten but not "unscrewed".
John C. Herman Mar. 7, 1893 U.S. Pat. No. 493,213: NUT LOCK, improvement in nut locks, consisting X shape section helically coiled spring material out of plane split ring having ends chamfered for biting surfaces in two places each end. Used for fish plate to nut locking, no elongated holes mentioned.
Elder E. Legge and Leonard C. Peskin Jun. 17, 1935 U.S. Pat. No. 2,089,924: COMBINED SPRING WASHER AND NUT LOCK, for severe and frequent vibration structures such as rail fastening and the like. Helio-conical plural spiral coiled strip of rectangular or elliptical section with sharp top and bottom edges of overlapping convolutions where upon joint closure forces offered cause crimped portions of the helix and then frictional resistance and internal pressure of washer produce hoop tension and bending within nesting adjacent convolutions, where relatively sharp edges engage the nut and bearing surfaces.
Masaharu Kubokawa Feb. 27, 1968 U.S. Pat. No. 3,370,632: LOCKING WASHERS comprising elastic far X section with resilient deformable 180 degree corners and 90 degree circular arcs as split helical ring with axially displaced ends initial flattening and secondary deformation of elastic X section by compression force in tightening of nut causes ring section deformation of corners within limit or elasticity.
Hayward A. Harvey Dec. 1, 1891 U.S. Pat. No. 464,301: RESILIENT SPIRAL WASHER AND MAKING OF THE SAME, provided quadrangular section with ratchet-shaped teeth transforming into curved ratchet or gouge shaped teeth upon coiling in to split ring shape and at tightening of nut, having teeth which may be or not be notched which are impacting nut surface and impacting object surface at intervals across either or both faces and tangential to circle of nearly the same diameter as the inside of the spiral.
Rudolph Buechting Apr. 23, 1935 U.S. Pat. No. 1,999,082: LOCK WASHER AND METHOD OF PRODUCING SAME, helical split ring angled or axially directed and centrally grooved with ribs corrugated radially milled on faces or face of a rectangular after coiling keystone section as to prevent radial spreading. Featured end has a pair of partial width circumfrentially directed cutting jaws and ribs intended to wear grooves in nut and work faces upon tightening nut. Method of production is by patent granted to G. K. Garrett, U.S. Pat. No. 1,560,228, excepting grooved faces of keystone section.
John B. O'Connor Jan. 13, 1959 U.S. Pat. No. 2,867,824: METHOD FOR MAKING SHEET MATERIAL SPLIT-RING LOCK WASHERS, helical split ring with sharp beveled ends of U section formed in continuous progressive roll forming line from coil of strip made to be spatially scored and notched by intermittent punch press.
State or the art and prior art references also include the following:
OWEN F. GARVEY Jun. 10, 1884 U.S. Pat. No. 299,977: WASHER, constructed to provide three or more arched sections with raised projecting radial edges of sharp points with opposite side edges and arches corresponding to provide resilient engagement upon flattening. This sheet stamped washer is not made from wire stock.
CARL S. OLSON May 1, 1928 U.S. Pat. No. 1,668,025: LOCK WASHER, sheet metal stamped annular ring with outer peripheral integral sharp pairs of teeth projecting out of plain disposed intermediate on other side to produce a wavy form when compressed.
Carl S. Olson Aug. 20, 1932 U.S. Pat. No. 1,874,597: LOCK WASHER, provides plural radial locking elements consisting of twisted square wire wherein inner and outer loops connect adjacent radial sections which may be alternately disposed out of plane. The multitude of loops with radial locking elements as represented would not practically fit under a standard hex nut without the wire cross section being minuscule, wherein tightening forces could considerably expand portions of the lock washer radially and possibly out from under the nut.
JOHN W. HOOVER. Feb. 23, 1965 U.S. Pat. No. 3,170,701: SEALING WASHER, pressure sealing composite metallic sheet metal or non metallic ring with a integral mooring portion having transverse web openings which allow pressure molding of elastomeric material through web openings and interconnecting the mooring ring. Elastomer is configured to provide sealing washer centering by closely approximating bolt diameter and also to provide sealing lips.
Known art lock washer disadvantages follow:
1. Standard ASA helical spring type locking only begins as back up loosening starts to allow end tooth to engage. With failure to engage an end tooth at either nut face or at work face, locking fails. Minimal spring engagement is evidenced by light, regular, heavy duty, and extra heavy duty, meaning more material is used due to weak cross section thickness. Spring type locking depends on friction of initial fastener tightening for joint security. Spring type are primarily used as nut lock, excepting high collar type, which is a screw lock. Both small sizes and large sizes have only one end tooth per side. PA1 2. Spring and tooth types become flat in tightened joint, so both known types behave like a flat washer under tightened nut. PA1 3. Split spring types easily tangle at splits with other like lock washers in packages and bulk storage bins. PA1 4. Both types readily fall off fastener in below horizontal screw positions, so they require hand holding while starting nut. PA1 5. Spring and tooth types are ineffective in severe service and severe vibration conditions. PA1 6. Both types generally have larger outside diameter than fastener head or nut. PA1 7. Both types have thickness, requiring extra bolt length. PA1 8. Both types add weight to fastened joint. PA1 9. Both types are assembles visible under fastener head or nut. PA1 10. Both types have edges angle, generally 90 degrees. PA1 11. Tooth type manufacture makes scrap from hole and skeleton. PA1 12. Tooth type cost 42% more than spring type, 1/2 inch size 1000 lot plain carbon material. PA1 First, that sharp crests actively and positively engage joint work surfaces continuously. The quantity of contacting crests made available is by design in choosing pitch length of axial reversed twists. PA1 Second, sharp crests do not become flat in joint, thereby eliminating dependance on friction for initial locking. PA1 Third, tangle free round formed locking ring in flat plane has fusion joined ends or abut ends that will not interconnect. PA1 Fourth, falling off fastener is eliminated by design of size of slight elliptical or faceted polygonal essentially round shape for joined end rings, and sized so that abut end rings may spring open slightly for gripping onto standard fastener shank or thread. PA1 Fifth, locking during severe vibration is effected by means of a multitude of sharp crests, each having continuous spring engaged contact with work and fastener surfaces. PA1 Sixth, outside diameter of locking ring is equal or less than fastener head or nut and also less than known art devices. PA1 Seventh, can be used in beveled openings to have no assembled joint thickness, therefor saving bolt length. PA1 Eighth, uses less material volume than standard or known art lock washers. Compared to regular series spring type, a locking ring saves 70% material volume for 1/2 inch screw size. Compared to regular series tooth type, a locking ring device saves 45% volume or saves 74% of material for 1/2 inch screw size, therefor weight is less. PA1 Ninth, can be assembled not visible by use in beveled opening. PA1 Tenth, deep penetration is positive by relatively sharp crests. PA1 Eleventh, manufacture of wire material and shape forming uses continuous scrapless processes. PA1 Twelfth, estimated at half the cost of spring type and at quarter the cost of tooth type. PA1 First, locking ring used under fastener head in beveled opening, both centers and locates the fastener axially and radially, stabilizing fastener in locked position. PA1 Second, using one or more locking ring locks two work members together, preventing torsional force from causing relative axial movement with only one fastener. PA1 Third, SEMS (R), pre-assembled fastener to lock washer, are currently made only as a not separable purchased item. But a locking ring can easily be separately assembled and stay on the fastner by design of locking ring formed shape or with an abut ends ring that springs open slightly for gripping fastener, saving considerable cost. PA1 Fourth, a plural fastener configured locking ring formed shape can be made for locating screws and holding them located in place for production assembly of one unitized item. This can save considerable assembly labor time, helping to automate screw tightening and locking by available multiple spindle multiple fastener tightening equipment. PA1 Fifth, locking rings have no size limitation, require no size specific dies. PA1 Sixth, locking rings are applicable for use with both left hand and right hand threaded fasteners. PA1 Seventh, locking rings can lock joint work members, lock joint work members to fasteners, lock fasteners, and lock combinations thereof. PA1 Eighth, both sealing and locking can be combined into one locking unit, offering corrosion protection within locked joint. PA1 Ninth, a straight portion of prepared reversed twist sharp crest spring wire material can be used as a locking key when placed in prepared work member grooves. This provides both lateral and longitudinal axis locking, unlike a machine key in key slot which locks only laterally. PA1 Tenth, gripping by lock ring can keep screw or fastener projecting through opening in place as preassembly, while awaiting nut. PA1 Eleventh, use of two or more locking rings on fastener in work members with beveled openings prevents fastener wobble or movement, thereby stiffening joint for extreme service and vibration. PA1 Twelfth, extended uses capability of locking ring device are evident and not available in known art washer type devices. PA1 Thirteenth, bending of wire section with continuous beaming overcomes spring back of flange in curl forming.